Optical assembly, backlight unit and display apparatus thereof

ABSTRACT

The present invention relates to an optical assembly, a backlight unit, and a display apparatus thereof. According to an embodiment of the present invention, an optical assembly includes a first layer, a plurality of light sources disposed over the first layer, a second layer that is disposed above the first layer and covering the plurality of light sources, and a pattern layer disposed above or in the second layer, wherein the pattern layer includes a plurality of patterns disposed at positions substantially corresponding to the light sources.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119(a) or §119(e), this application claims thebenefit of earlier filing date and right of priority to KoreanApplication Nos. 10-2009-0079700, filed on Aug. 27, 2009,10-2009-0079710 filed on Aug. 27, 2009, 10-2009-0080249 filed on Aug.28, 2009, 10-2009-0114226 filed on Nov. 24, 2009, 10-2009-0114227 filedon Nov. 24, 2009, and 10-2009-0114225 filed on Nov. 24, 2009 and U.S.Provisional Application No. 61/237,587 filed on Aug. 27, 2009. Each ofthese applications are hereby incorporated by reference herein in theirentirety.

FIELD OF THE INVENTION

The present invention relates to an optical assembly, a backlight unit,and a display apparatus thereof.

DISCUSSION OF THE RELATED ART

With development of an information society, a requirement for a displayapparatus is also being increased in various forms. Various displayapparatuses such as a liquid crystal display (LCD) apparatus, a plasmadisplay panel (PDP), an electro luminescent display (ELD), a vacuumfluorescent display (VFD), etc. have been recently researched and usedby complying with the requirement.

Among various display apparatuses, a liquid crystal panel of the LCDincludes a liquid crystal layer, and a TFT substrate and a color filtersubstrate that are opposed to each other with the liquid crystal layerinterposed therebetween. Since the liquid crystal panel has noself-luminous intensity, the liquid crystal panel can display an imageby using light provided from a backlight unit. As the backlight unit, aflorescent lamp disposed along one side of the LCD can be used. However,such a backlight unit has a limitation of producing an LCD device thatmay not be slim.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a backlight unitcapable of improving an image quality of a display picture and abacklight unit and a display apparatus thereof.

Another object of the present invention is to provide a backlight unit,an optical assembly, and a display apparatus, which address thelimitations and disadvantages associated with the related art.

According to an aspect of the present invention, a backlight unit canreduce the thickness of a display apparatus and improve an exteriorwhile simplifying a manufacturing process of the display apparatus byclosely contacting the backlight unit to a display panel.

Further, it is possible to provide light having uniform luminance to thedisplay panel by disposing the backlight unit so that a plurality oflight sources emit in different directions. Accordingly, it is possibleto improve the image quality of the display picture.

According to another aspect, the present invention provides an opticalassembly, comprising: a first layer; a plurality of light sourcesdisposed over the first layer; a second layer that is disposed above thefirst layer and covering the plurality of light sources; and a patternlayer disposed above or in the second layer, wherein the pattern layerincludes a plurality of patterns disposed at positions substantiallycorresponding to the light sources.

According to another aspect, the present invention provides an opticalassembly, comprising: a first layer; a plurality of light sourcesdisposed over the first layer; and a second layer disposed above thefirst layer and covering the plurality of light sources, the secondlayer including a plurality of patterns for selectively reflecting lightemitted from the plurality of light sources, wherein the plurality ofpatterns are disposed at positions corresponding substantially to theplurality of light sources.

According to another aspect, the present invention provides a backlightunit, comprising at least one optical assembly including: a first layer;a plurality of light sources disposed over the first layer; a secondlayer that is disposed above the first layer and covering the pluralityof light sources; and a pattern layer disposed above or in the secondlayer, wherein the pattern layer includes a plurality of patternsdisposed at positions substantially corresponding to the light sources.

According to another aspect, the present invention provides a displayapparatus, comprising: a backlight unit including at least one opticalassembly; and a display panel positioned above the backlight unit,wherein the backlight unit is divided into a plurality of blocks and isselectively drivable for the divided blocks. The optical assemblyincludes a first layer; a plurality of light sources disposed over thefirst layer; a second layer that is disposed above the first layer andcovering the plurality of light sources; and a pattern layer disposedabove or in the second layer, wherein the pattern layer includes aplurality of patterns disposed at positions substantially correspondingto the light sources.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentinvention will become more apparent upon consideration of the followingdescription of preferred embodiments, taken in conjunction with theaccompanying drawing figures.

FIG. 1 is an exploded perspective view illustrating a configuration of adisplay apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic configurationof a display module according to an embodiment of the present invention.

FIGS. 3 and 4 are cross-sectional views illustrating configurations of abacklight unit according to a first embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a configuration of abacklight unit according to a second embodiment of the presentinvention.

FIG. 6 is a cross-sectional view illustrating a configuration of abacklight unit according to a third embodiment of the present invention.

FIGS. 7 to 12 are cross-sectional views illustrating configurations of abacklight unit according to a fourth embodiment of the presentinvention.

FIGS. 13 to 16 are plan views illustrating embodiments of placement of apattern formed in a backlight unit according to the present invention.

FIGS. 17A to 17D are diagrams illustrating embodiments of a shape of apattern in a backlight unit according to the present invention.

FIGS. 18 and 19 are cross-sectional views illustrating a configurationof a backlight unit according to a fifth embodiment of the presentinvention.

FIGS. 20A and 20B are cross-sectional views illustrating two examples ofa configuration of a backlight unit according to a sixth embodiment ofthe present invention.

FIGS. 21 and 22 are cross-sectional views for explaining a positionalrelationship between a light source and a reflection layer that areprovided in a backlight unit according to an embodiment of the presentinvention.

FIGS. 23 and 24 are cross-sectional views illustrating examples of astructure of a light source according to an embodiment of the presentinvention.

FIGS. 25 to 27 are cross-sectional views and

FIGS. 28 and 29 are plan views, illustrating configurations of abacklight unit according to a seventh embodiment of the presentinvention.

FIG. 30 is a cross-sectional view illustrating one embodiment ofstructures of a plurality of light sources that are provided in abacklight unit according to the present invention.

FIGS. 31 to 35 are plan views illustrating embodiments of a structure inwhich a plurality of light sources are disposed in a backlight unitaccording to the present invention.

FIGS. 36 to 39 are plan views illustrating first examples of a structureof a reflection layer that is provided in a backlight unit according tothe present invention.

FIG. 40 is a plan view illustrating a second example of a structure of areflection layer that is provided in a backlight unit according to thepresent invention.

FIG. 41 is a plan view illustrating a third example of a structure of areflection layer that is provided in a backlight unit according to thepresent invention.

FIG. 42 is a plan view illustrating a forth example of a structure of areflection layer that is provided in a backlight unit according to thepresent invention.

FIG. 43 is a plan view illustrating one embodiment of a configuration ofa backlight unit with a plurality of optical assemblies according to thepresent invention.

FIG. 44 is a cross-sectional view illustrating a configuration of adisplay apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawing figures which form a part hereof, and which show byway of illustration embodiments of the invention. It is to be understoodby those of ordinary skill in this technological field that otherembodiments and examples may be utilized, and structural, electrical, aswell as procedural changes may be made without departing from the scopeof the present invention. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or similarparts.

FIG. 1 is an exploded perspective view illustrating a configuration of adisplay apparatus according to an embodiment of the invention. Thedisplay apparatus here is preferably an LCD type, but can be of anotherdisplay type.

Referring to FIG. 1, the display apparatus 1 can include a displaymodule 20, a front cover 30 and a back cover 40 covering the displaymodule 20, a fixation member 50 for fixing the display module 20 to thefront cover 30 and/or the back cover 40.

Meanwhile, the front cover 30 can include a front panel made of atransparent material, which transmits light. The front panel is disposedin the display module 20, more particularly, in the front of a displaypanel included in the display module 20 to protect the display module 20from an external shock and to show a picture displayed in the displaymodule 20 by transmitting the light emitted from the display module 20to the outside.

One side of the fixation member 50 is fixed to the front cover 30 by afastening member such as a screw, for example and the other sidesupports the display module 20 to the front cover 30 to fix the displaymodule 20 to the front cover 30.

In the embodiment, the fixation member 50 has a plate shape that extendslengthily in one direction, for example, but the additional fixationmember 50 may not be provided and the display module 20 can beconfigured to be fixed to the front cover 30 or the back cover 40 by thefastening member.

FIG. 2 is a cross-sectional view illustrating a schematic configurationof a display apparatus according to an embodiment of the presentinvention. The display module 20 provided in the display apparatus ofFIG. 1 can be configured to include a display panel 100 and a backlightunit 200 as shown in FIG. 2. Particularly, the display module 20includes the backlight unit 200 preferably extending with the displaypanel 100 so that the backlight unit 200 is disposed below andcorresponds to the image displaying region of the display panel 100. Forexample, the size of the backlight unit 200 may be the same as orsimilar to the size of the display panel 100. The display apparatus ofFIG. 2 is preferably an LCD type, but may be of another display type.

Referring to FIG. 2, the display panel 100 for displaying images thereonincludes a color filter substrate 110 and a thin film transistor (TFT)substrate 120 that are opposed to each other and attached to have auniform cell gap. A liquid crystal layer can be interposed between thetwo substrates 110 and 120.

The color filter substrate 110 includes a color filter including red(R), green (G), and blue (B) color filter portions and can generate animage corresponding to a red, green, or blue color when the light isapplied.

Meanwhile, the pixels can be composed of the red, green, and bluesub-pixels, but is not limited thereto like one example in which red,green, blue, and white (W) sub-pixels configure one pixel and the pixelcan be configured by various combinations.

The TFT substrate 120 includes a plurality of TFTs arranged preferablyin a matrix configuration, and each of the TFTs can selectively switch apixel electrode as a switching device. For example, a common electrodeand the pixel electrode can transform the array of molecules of theliquid crystal layer depending on a predetermined voltage applied fromthe outside.

The liquid crystal layer is composed of a plurality of liquid crystalmolecules. The liquid crystal molecules change the array in accordancewith a voltage difference generated between the pixel electrode and thecommon electrode. As a result, light provided from the backlight unit200 can be inputted into the color filter substrate 110 in accordancewith the change of the array of the molecules of the liquid crystallayer. Further, an upper polarizer 130 and a lower polarizer 140 can bedisposed on the top and the bottom of the display panel 100,respectively, and more particularly, the upper polarizer 130 can beformed on the top of the color filter substrate 110 and the lowerpolarizer 140 can be formed on the bottom of the TFT substrate 120.

Meanwhile, a gate drive and a data driver that generate driving signalsfor driving the panel 100 can be provided on the side of the displaypanel 100.

The structure and configuration of the display panel 100 are just oneexample and modification, addition, and deletion the embodiment can bemade within the scope without departing from the spirit of the presentinvention. That is, the display panel 100 can be any known display panelthat can be used with the backlight unit 200.

As shown in FIG. 2, the display apparatus according to the embodiment ofthe present invention can be configured by closely disposing thebacklight unit 200 to the back of the entire surface of the displaypanel 100.

For example, the backlight unit 200 can be bonded and fixed onto thebottom surface of the display panel 100, more particularly, the lowerpolarizer 140. For this, an adhesive layer can be interposed between thelower polarizer 140 and the backlight unit 200.

As described above, it is possible to reduce the entire thickness of thedisplay apparatus by closely contacting the backlight unit 200 to theback surface of the display panel 100, thereby improving the exterior ofthe display apparatus and it is possible to simplify the structure andmanufacturing process of the display apparatus by removing a structurefor fixing the backlight unit 200.

Further, by removing a gap between the backlight unit 200 and thedisplay panel 100, it is possible to prevent malfunction of the displayapparatus or deterioration in an image quality of a display picture thatis caused due to the insertion of foreign substances, etc. into the gap.

According to the embodiment of the present invention, the backlight unit200 can be configured by laminating a plurality of function layers, andat least one layer of the plurality of function layers can be providedwith a plurality of light sources.

Further, as described above, it is preferable that the backlight unit200, more particularly, a plurality of layers configuring the backlightunit 200 are made of flexible materials, respectively, so as to closelyfix the backlight unit 200 onto the bottom surface of the display panel100.

In addition, a bottom cover on which the backlight unit 200 is seatedcan be provided on the bottom of the backlight unit 200.

According to the embodiment of the present invention, the display panel100 can be divided into a plurality of regions. The brightness of lightemitted from a corresponding region of the backlight unit 200, that is,the brightness of the corresponding light source is adjusted inaccordance with a gray peak value or a color coordinate signal of eachof the divided regions, such that the luminance of the display panel 100can be adjusted.

For this, the backlight unit 200 can operate by being divided into aplurality of division driving regions corresponding to the dividedregions of the display panel 100, respectively.

FIG. 3 is a cross-sectional view illustrating a configuration of abacklight unit according to a first embodiment of the present invention.The illustrated backlight unit 200 can include a first layer 210, lightsources 220, a second layer 230, and a reflection layer 240. The lightsources 220 in the backlight unit 200 are formed below the display panel100 for providing light throughout the display panel 100 as shown inFIGS. 1 and 2.

Referring to FIG. 3, the plurality of light sources 220 are formed onthe first layer 210 and the second layer 230 is disposed on the top ofthe first layer 210 to cover the plurality of light sources 220.Preferably the second layer 230 completely encapsulates the lightsources 220 formed on the first layer 210, but in another example, thessecond layer 230 can cover only certain portions/sides of the lightsources 220 formed on the first layer 210.

The first layer 210 may be a substrate on which the plurality of lightsources 220 are mounted. An electrode pattern for connecting the lightsource 220 with an adapter for supplying power may be formed on thefirst layer 210. For example, a carbon nanotube electrode pattern forconnecting the adapter with the light source 220 can be formed on thetop of the substrate.

Meanwhile, the first layer 210 is formed by usingpolyethyleneterephthalate, glass, polycarbonate, silicon, etc. and maybe a printed circuit board (PCB) substrate on which the plurality oflight sources 220 are mounted and may have a film shape.

Each light source 220 may be a light emitting diode (LED) chip or one oflight emitting diode packages with at least one light emitting diodechip. In the embodiment, one example in which the light emitting diodepackage is provided as the light source 220 will be described.

Meanwhile, the LED packages configuring the light sources 220 can beclassified into a top view scheme and a side view scheme in accordancewith a direction in which a light emitting surface faces. Each lightsource 220 according to the embodiment of the present invention can beconfigured by using at least one of the top view-type LED package inwhich the light emitting surface of the LED package is the top surfaceof the LED package (e.g., the light is emitted upwardly or in a verticaldirection) and the side view-type LED package in which the lightemitting surface of the LED package is a side surface of the LED package(e.g., the light is emitted to the side of the LED package or in ahorizontal direction).

Further, each light source 220 can be configured by a colored LED or awhite LED emitting at least one color among colors such as red, blue,and green colors, etc. In addition, the colored LED can include at leastone of a red LED, a blue LED, and a green LED. The disposition andemitting light of the light emitting diode can be changed within atechnical scope of the embodiments.

Meanwhile, the second layer 230 formed to be disposed on the top of thefirst layer 210 to cover the plurality of light sources 220 canuniformly provide the light emitted from the light sources 220 to thedisplay panel 100 by transmitting and diffusing the light emitted fromthe light sources 220.

The reflection layer 240 that reflects the light emitted from the lightsources 220 can be formed between the first layer 210 and the secondlayer 230, e.g., on the top of the first layer 210 but below the secondlayer 230. The reflection layer 240 can more widely diffuse the lightemitted from the light sources 220 by reflecting the lightfull-reflected from a boundary of the second layer 230 again.

The reflection layer 240 can use a sheet to which a white pigment suchas titanium oxide is dispersed to a sheet made of a synthetic resin, asheet laminated with a metal deposition film onto the surface thereof, asheet in which a bubble is dispersed so as to diffuse the light to asheet made of the synthetic resin, etc. The surface of the reflectionlayer 240 may be coated with silver (Ag) so as to increase thereflectance. Meanwhile, the reflection layer 240 may be coated on thetop of the first layer 210 which is the substrate.

The second layer 230 can be formed with a light transmissive material,e.g., silicon or an acrylic resin. However, the second layer 230 is notlimited to the above-mentioned material and can be formed with variousresins in addition to the above-mentioned material.

Further, the second layer 230 can be made of a resin having a refractiveindex of approximately 1.4 to 1.6 so that the backlight unit 200 canhave uniform luminance by diffusing the light emitted from the lightsources 220.

For example, the second layer 230 can be made of any one materialselected from a group consisting of polyethyleneterephthalate,polycarbonate, polypropylene, polyethylene, polystyrene and polyepoxy,silicon, acryl, etc.

The second layer 230 can include a polymer resin having predeterminedadhesion so as to be tightly and closely adhere to the light sources 220and the reflection layer 240. For example, the second layer 230 can beconfigured to include an acrylic resin such as unsaturated polyester,methylmethacrylate, ethylmethacrylate, isobutylmethacrylate, normalbutylmethacrylate, normal butylmethylmethacrylate, acrylic acid,methacrylic acid, hydroxy ethylmethacrylate, droxy propylmethacrylate,hydroxy ethylacrylate, acrylamide, methylol acrylamide, glycidylmethacrylate, ethylacrylate, isobutylacriate, normal butylacrylate,2-ethylhexyl acrylate polymer, or copolymer, or terpolymer, etc., anurethane resin, an epoxy resin, a melamine resin, etc.

The second layer 230 may be formed by applying and curing a liquid orgel-type resin onto the top of the first layer 210 where the pluralityof light sources 220 and the reflection layer 240 are formed or thesecond layer 230 may be formed by adhering onto the top of the firstlayer 210 by being separately fabricated.

Meanwhile, as the thickness ‘a’ of the second layer 230 increases, thelight emitted from the light sources 200 is more widely diffused, suchthat the light having uniform luminance can be provided to the displaypanel 100 from the backlight unit 200. In contrast, as the thickness ‘a’of the second layer 230 increases, the quantity of light which isabsorbed in the second layer 230 can increase. Therefore, the luminanceof the light provided to the display panel 100 from the backlight unit200 can uniformly decrease.

Accordingly, in order to provide the light having uniform luminancewhile not largely decreasing the luminance of the light provided to thedisplay panel 100 from the backlight unit 200, it is preferable that thethickness ‘a’ of the second layer 230 is in the range of 0.1 to 4.5 mmor approximately 0.1 to 4.5 mm.

FIG. 4 is a cross-sectional view of a region of a backlight unit 200,where light sources 220 are not disposed (e.g., a region between thelight sources 220). A description of the same components of theillustrated backlight unit 200 as those explained by referring to FIGS.2 to 3 will now be omitted.

By using the backlight unit 200 shown in FIG. 31 as an example, thecross-sectional view shown in FIG. 3 shows a cross-sectionalconfiguration of a region where the light sources 220 are positioned inthe backlight unit 200 taken along line A-A′ and the cross-sectionalview shown in FIG. 4 shows a cross-sectional configuration of a regionwhere the light sources 200 are not positioned taken along line B-B′.

Referring to FIG. 4, the region where the light sources 220 are notpositioned may have a structure in which the reflection layer 240 coversthe top of the first layer 210. In this region, for example, thereflection layer 240 is formed on the first layer 210 without the holesinto which the light sources 220 can be inserted. Instead, such holesare formed in regions of the reflection layer 240 corresponding to thepositions of the light sources 220, and the light sources 220 areprotruded upward through the holes of the reflection layer 240 to becovered by the second layer 230 as shown in FIG. 3.

Hereinafter, the configuration of the backlight unit 200 according tothe embodiment(s) of the present invention will be described in detailby using a case in which the first layer 210 provided in the backlightunit 100 is a substrate where the plurality of light sources 200 areformed and the second layer 230 is a resin layer made of a predeterminedresin as one example.

FIG. 5 is a cross-sectional view illustrating a configuration of abacklight unit according to a second embodiment of the presentinvention. Description of the same components of the backlight unit 200shown in FIG. 5 as those explained by referring to FIGS. 2 and 3 willnow be omitted.

Referring to FIG. 5, the plurality of light sources 220 can be mountedon the substrate 210 and the resin layer 230 can be disposed on the topof the substrate 210 to cover the light sources 230 entirely orpartially. Meanwhile, the reflection layer 240 can be formed between thesubstrate 210 and the resin layer 230, e.g., on the top of the substrate210.

Further, as shown in FIG. 5, the resin layer 230 can include a pluralityof scattering particles 231 and the scattering particles 231 can morewidely diffuse the light emitted from the light sources 220 byscattering or refracting the incident light.

The scattering particles 231 can be made of a material having arefractive index different from the material forming the resin layer230, e.g., a material having a refractive index higher than that of thesilicon-type or acrylic resin forming the resin layer 230 so as toscatter or refract the light emitted from the light sources 220.

For example, the scattering particles 231 can be configured bypolymethylmethacrylate/styrene copolymer (MS), polymethylmethacrylate(PMMA), polystyrene (PS), silicon, titanium dioxide (TiO₂), silicondioxide (SiO₂), etc. and can be configured by combining the materials.

Meanwhile, the scattering particles 231 can be configured even by amaterial having a refractive index lower than that of the materialforming the resin layer 230 and for example, can be configured byforming the bubbles in the resin layer 230.

Further, the material for forming the scattering particle 231 is notlimited to the above-mentioned materials and the scattering particle 231can be configured by using various polymer materials or inorganicparticles other than the above-mentioned materials.

According to the embodiment(s) of the present invention, the resin layer230 can be formed by mixing the scattering particles 231 with theliquid-type or gel-type resin, and applying them onto the top of thefirst layer 210 where the plurality of light sources 220 and thereflection layer 240 are formed.

Referring to FIG. 5, an optical sheet 250 can be disposed on the top ofthe resin layer 230 and for example, the optical sheet 250 can includeone or more prism sheets 251 and/or one or more diffusion sheets 252.

In this case, a plurality of sheets included in the optical sheet 250are provided by being closely contacting each other without beingseparated from each other, such that it is possible to minimize orreduce the thickness of the optical sheet 250 or the backlight unit 200.

Meanwhile, the bottom of the optical sheet 250 can be closely contactedto the resin layer 230 and the top of the optical sheet 250 can beclosely contacted onto the bottom of the display panel 100, e.g., on thelower polarizer 140.

The diffusion sheet 252 prevents light emitted from the resin layer 230from being partially focused by diffusing the incident light to therebymaking the luminance of the light more uniform. Further, the prism sheet251 allows the light to be vertically inputted into the display panel100 by focusing the light emitted from the diffusion sheet 252.

According to another embodiment of the present invention, the opticalsheet 250, for example, at least one of the prism sheet 251 and thediffusion sheet 252 can be removed or the optical sheet 250 can beconfigured by including various function layers in addition to the prismsheet 251 and the diffusion sheet 252.

Further, a plurality of holes or indentations may be formed at positionsof the reflection layers 240 corresponding to the plurality of lightsources 220 so that the plurality of light sources 220 to be disposed onthe lower substrate 210 may be inserted into the holes or indentations.

In this case, the light sources 220 are inserted in a lower part throughthe holes formed in the reflection layer 240 and at least some of thelight sources 220 may protrude on the top of the reflection layer 240.

As such, it is possible to further improve the fixation force betweenthe substrate 210 mounted with the light sources 220 and the reflectionlayer 240 by configuring the backlight unit 200 by using the structurein which the light sources 220 are inserted into the holes of thereflection layer 240.

FIG. 6 is a cross-sectional view illustrating a configuration of abacklight unit according to a third embodiment of the present invention,and depicts an example of the light sources 220 inserted within theindentations/holes defined through the reflections layer 240.Description of the same components of the backlight unit 200 shown inFIG. 6 as those explained by referring to FIGS. 2 to 5 will now beomitted.

Referring to FIG. 6, each of the plurality of light sources 220 providedin the backlight unit 200 has the light emitting surface on the sidesurface thereof and can emit light in a lateral direction, e.g., adirection in which the substrate 210 or the reflection layer 240 extendsabove the substrate 210.

For example the plurality of light sources 220 can be configured byusing the side view-type LED packages. As a result, it is possible toreduce a limitation that the light source 220 is observed as a hot spoton a screen, and it is possible to produce a slim backlight unit 200 andthus a slim display apparatus by reducing the thickness ‘a’ of the resinlayer 230.

In this case, each light source 220 can emit light having an orientationangle α of, for example, 90 to 150 degrees centering on a firstdirection X (indicated by an arrow). Hereinafter, light emitted from thelight source 220 is represented as being emitted in the first directionX (indicated by the arrow).

According to an embodiment of the present invention, a reflectionpattern is formed on the top of the resin layer 230 to reflect anddiffuse the light upwards from the light sources 220, thereby emittingthe light having more uniform luminance from the backlight unit 200.These features are described in more detail referring to FIGS. 7 to 10.

FIGS. 7 to 12 are cross-sectional views illustrating configurations of abacklight unit of a display apparatus according to a fourth embodimentof the present invention. A description of the same components of thebacklight unit 200 shown in FIGS. 7 to 12 as the components explained byreferring to FIGS. 1 to 6 will now be omitted. Each of the light sources220 in FIGS. 7 to 12 preferably emits light to the side from a sidesurface of the light source, e.g., as shown in FIG. 6, but as avariation, may emit light from the top surface of the light source.

Referring to FIG. 7, a pattern layer including a plurality of patterns232 may be formed on the top of the resin layer 230 of the backlightunit 200 including the light sources 220. More specifically, theplurality of patterns 232 included in the pattern layer may be formed onthe resin layer 230 to correspond respectively to the positions whereeach of the light sources 220 is disposed.

For example, the patterns 232 formed on the top of the resin layer 230may be a reflection pattern that reflects at least a part of the lightemitted from the light source 220. As shown in FIG. 7, it is possible toreduce the luminance of light emitted from an area adjacent to eachlight source 220 by forming the reflection patterns 232 on the resinlayer 230, thereby causing the backlight unit 200 to emit light having auniform luminance.

That is, each reflection pattern 232 is formed on the resin layer 230 tocorrespond to a position where each of the plurality of light sources220 is formed to reduce or control selectively the luminance of thelight emitted from the area directly above each light source 220 and thearea adjacent to each light source 220 by selectively reflecting thelight emitted from an area above the top surface of each light source.The reflected light may be diffused to a lateral direction.

More specifically, the light emitted upwardly from each light source 220is reflected selectively downwards while being diffused in the lateraldirection by the reflection pattern 232, and the light reflected by thereflection pattern 232 may be reflected upwards while being diffused inthe lateral direction by the reflection layer 240 again. That is, thereflection patterns 232 may reflect 100% of the light impinging thereon,or may reflect a portion of the light impinging thereon whiletransmitting a portion of the same light. As such, the characteristicsof the reflection patterns 232 can be modified to control the lightpropagation through the resin layer 230 and the patterns 232.

As a result, the light emitted from the light sources 220 can be widelydiffused in the lateral direction and in other directions withoutconcentrating on the upper direction so as to allow the backlight unit200 to emit the light having a more uniform luminance.

The reflection patterns 232 include a reflection material such as metal,etc. For example, the reflection pattern 232 may include metal such asaluminum, silver, gold, or the like having a reflectance of 90% or more.For example, the reflection patterns 232 may be formed with a materialsuch that about 10% or less of the total light impinging thereon wouldbe transmitted therethrough while the remaining % (or less) of the totallight would be reflected by the reflection patterns 232.

In this case, the reflection patterns 232 may be formed by depositing orcoating the metal. As another method, the reflection patterns 232 may beformed by performing a printing operation using reflection ink includingthe metal, for example, silver ink in accordance with a predeterminedpattern.

Further, in order to improve a reflective effect of the reflectionpattern 232, a color of the reflection pattern 232 may have a colorclose to a color having a high brightness, for example, a white color.For example, the reflection pattern 232 may have a color having a higherbrightness than that of the resin layer 230.

Meanwhile, the reflection patterns 232 may include metal oxide. Forexample, the reflection patterns 232 may include titanium dioxide(TiO₂). More specifically, the reflection patterns 232 may be formed byperforming the printing operation using reflection ink includingtitanium dioxide (TiO₂).

FIGS. 8 through 12 illustrate other examples of forming a plurality ofpatterns 232 to correspond to the positions of light sources 220according to the invention. A description of the same components of thebacklight unit 200 shown in FIGS. 8 to 12 as the components explained byreferring to FIGS. 1 to 7 will now be omitted.

Referring to FIGS. 8 to 10, the case where the plurality of reflectionpatterns 232 are formed to correspond to the positions of the lightsources 220 may include a case where the center of each reflectionpattern 232 is formed to coincide with (or substantially coincide with)the center of the corresponding light source 220 (e.g., FIG. 7) and acase where the center of each reflection pattern 232 is spaced from thecenter of the corresponding light source 220 by a predetermined gap(e.g., FIG. 8, 9 or 10).

According to one example of the present invention, as shown in FIG. 8,the center of each reflection pattern 232 may not coincide with thecenter of the corresponding light source 220.

For example, when the light emitting surface of the light source 220faces not the upper direction but the lateral direction and therefore,the light is emitted from the light source 220 in the lateral direction,then the luminance level of the light emitted from the side surface ofeach light source 220 may decrease as the light travels through theresin layer in a direction indicated by an arrow in FIG. 8. As a result,a first area immediately adjacent to the light emitting surface of thelight source 220 may have a higher luminance than adjacent areas.Therefore, the reflection patterns 232 may be formed by extending offcenter from the corresponding light source 220 in the directionindicated by the arrow of light emitted from the light source 220.

For example, the center of the reflection pattern 232 may be formed at aposition slightly deviated from the center of the corresponding lightsource 220 in the light emitting direction.

According to another example, referring to FIG. 9, the reflectionpattern 232 may be formed at a position further moved in a lightemission direction than the reflection pattern 232 shown in FIG. 8.

For example, the gap between the center of the reflection pattern 232and the center of the light source 220 corresponding thereto may furtherincrease than the gap shown in FIG. 8. For example, as shown in FIG. 9,the light emission surface of the light source 220 may be superimposedon a left end portion of the reflection pattern 232, or the end of thereflection pattern 232 may correspond to the light emission surface ofthe light source 220.

In another example, referring to FIG. 10, the reflection pattern 232 maybe formed at a position further moved in the light emission direction(indicated by an arrow) than the reflection pattern 232 shown in FIG. 9.

For example, as shown in FIG. 10, the region where the reflectionpattern 232 is formed may not be superimposed on the region where thecorresponding light source 220. Therefore, the left end portion of thereflection pattern 232 may be spaced from the light emission surface ofthe light source 220 by a predetermined gap.

According to yet another embodiment of the present invention, as shownin FIG. 11, the reflection patterns 232 may be formed within the resinlayer 230. In another variation, the reflections patterns 232 which areoff centered from the light sources 220 (e.g., as shown in FIGS. 8 to10) may formed within the resin layer 230.

Referring to FIG. 12, the reflection patterns 232 may be manufactured ina sheet form. In this case, the pattern layer including the plurality ofreflection patterns 232 may be formed on the resin layer 230.

For example, after the pattern layer is configured by forming theplurality of reflection patterns 232 on one surface of a transparentfilm 260 through printing, etc., the pattern layer including thetransparent film 260 may be formed on the resin layer 230. Morespecifically, the reflection patterns 232 may be formed by printing thetransparent film with a plurality of dots.

Meanwhile, as a ratio of an area where the reflection pattern 232 isformed in or on the resin layer 230 increases, an opening ratiodecreases, such that the overall luminance of light provided from thebacklight unit 200 to the display panel 100 may decrease. The openingratio here indicates an amount of area where portions of the reflectionpattern 232 is not formed within the reflection pattern 232, and throughthis area, the light may be transmitted. Therefore, in order to preventthe image quality of the pictures displayed by the display panel 100from being deteriorated due to a rapid decrease in the luminance of thelight provided to the display panel 100, the opening ratio of thepattern layer on which the reflection pattern 232 is formed ispreferably at 70% or more. That is, the area where the reflectionpattern is formed in the resin layer 230 preferably occupies 30% or lessof the entire area.

FIG. 13 to are plan views illustrating various examples of placement ofa pattern formed in a backlight unit for a display apparatus accordingto an embodiment of the invention. As described above, each reflectionpattern 232 may be formed for the corresponding light source 220. Here,the reflection pattern 232 may be formed in or on the correspondinglight source 220, e.g., as shown in FIGS. 7 to 12.

For example, as shown in FIG. 13, each reflection pattern 232 may have acircular shape or an oval shape centering on (or off-centered from) theposition where the corresponding light source 220 is formed. However,each reflection pattern 232 can have a different shape and/or size.

In another example, referring to FIG. 14, the reflection pattern 232 maybe positioned by being moved from the center position of FIG. 13 to theleft or right (depending on the location of the corresponding lightsource 220) in or towards the light emission direction (indicated by thearrows), that is, along an x-axis direction. Therefore, the center ofthe reflection pattern 232 may be spaced from the position where thecenter of the light source 220 corresponding thereto is formed in thelight emission direction by a predetermined gap.

In still another example, referring to FIG. 15, the reflection pattern232 may be positioned by further being moved in the light emissiondirection than the reflection pattern 232 shown in FIG. 14. Therefore,only a partial region of the region where the light source 220 is formedmay be superimposed on the region where the reflection pattern 232 isformed.

In still another example, referring to FIG. 16, the reflection pattern232 may be positioned outside of the region where the light source 220is formed by further being moved in the light emission direction thanthe reflection pattern 232 shown in FIG. 15. Therefore, the region wherethe light source 220 is formed may not be superimposed (or overlap) onthe region where the reflection pattern 232 is formed.

FIGS. 17A to 17D are top plan views of a reflection pattern 232 forillustrating different examples of the shape of one reflection pattern232 corresponding preferably to a light source 220 according to theinvention. Each reflection pattern 232 of FIGS. 17A-17D can be used asthe reflection pattern 232 of FIGS. 7 to 16. For example, eachreflection pattern 232 may be composed of a plurality of dots orportions, each dot or portion including a reflection material, forexample, metal or metal oxide.

Referring to FIG. 17A, in this example, each reflection pattern 232 mayhave a circle or cylinder shape (or other shape, e.g., diamond shape,etc.) centering on (or off-centered from) the area where the lightsource 220 is formed and the reflectance of the reflection pattern 232may decrease outwards from a center 234 of the reflection pattern 232.The reflectance of the reflection pattern 232 may decrease graduallyfrom the center 234 to its outer areas by having a less number of dotsas one moves from the center 234 to the outer areas as shown and/or bydecreasing the reflectance characteristics of the material in thepattern 232 as one moves from the center 234 to the outer areas.Further, the light transmittance or opening ratio of the reflectionpattern 232 may increase outwards from the center 234 to the outerareas.

As a result, the position where the light source 220 is formed, morespecifically, the center 234 of the reflection pattern 232 correspondingto the center of the light source 220 may have the highest reflectance(e.g., no or little light is transmitted therethrough), and the lowesttransmittance or opening ratio. Therefore, it is possible to moreeffectively prevent the hot spot from being generated due to theconcentration of light on the area where the light source 220 is formed.

In one example, in order to prevent the hot spot from being generated,according to an embodiment of the invention, an opening ratio of eachreflection pattern 232 which is formed above the light source 220 may bepreferably 5% or less.

If the plurality of dots 233 constituting the reflection pattern 232 areprovided, gaps between adjacent dots 233 may increase outwards from thecenter 234 to the outer areas and as a result, the transmittance or theopening ratio of the reflection pattern 232 increases while thereflectance of the same reflection pattern 232 decreases outwardly fromthe center 234 of the reflection pattern 232 to its outer areas asdescribed above.

In another example, referring to FIG. 17B, each reflection pattern 232may have an oval shape. The center 234 of this reflection pattern 232may coincide with the center of the corresponding light source 220. As avariation, however, as shown in FIG. 17B, the center 234 of thereflection pattern 232 may not coincide with the center of the lightsource 220, and the center 234 may be off-centered from the center ofthe light source 220.

That is, as described by referring to FIGS. 8 to 10, the center 234 ofthe reflection pattern 232 may be formed at a position slightly deviatedfrom the center of the corresponding light source 220 in one direction,for example, the direction of the light being emitted from the lightsource 220. For example, the portion 235 may coincide with the center ofthe corresponding light source 220. In this case, the reflectance of thereflection pattern 232 may decrease or the transmittance thereof mayincrease outwardly from a portion 235 of the reflection pattern 232corresponding to the center of the light source 220.

In FIG. 17B, the portion 235 of the reflection pattern 232 correspondingto the center of the light source 220 may be positioned deviated fromthe center 234. The portion 235 of the reflection 234 corresponding tothe center of the light source 220 may have the highest reflectance orthe lowest transmittance.

Referring to FIGS. 17C and 17D, each reflection pattern 232 may have arectangle, a square, or a diamond shape centering on the area where thecorresponding light source 220 is formed, and may have a reflectancethat decreases as one moves from the center of the reflection pattern232 to its outer areas, and an opening ratio that increases outwardlyfrom the center thereof to its outer areas. Features pertaining to thereflection pattern 232 of FIGS. 17A and 17B can be equally applicable tothe reflection pattern 232 of FIGS. 17C and 17D.

Even in this case, in order to prevent the hot spot from beinggenerated, a central area of the reflection pattern 232 whichsuperimposes or disposed over the corresponding light source 220preferably has an opening ratio of 5% or less.

Meanwhile, as shown in FIGS. 17C and 17D, in case of the plurality ofdots 233 constituting the reflection pattern 232, the size of each gapbetween adjacent dots 233 may increase outwardly from the center of thereflection pattern 232 to its outer areas.

As shown in FIGS. 17A to 17D, when the reflection pattern 232 accordingto the present invention is used, the hot spot phenomenon in which thelight density concentrates on the area adjacent to the light source 220is reduced significantly. For example, the light intensity isdistributed out more throughout the light source area and adjacentareas.

In the above description, although the cases in which the reflectionpattern 232 includes the plurality of dots by referring to FIGS. 17A to17D are discussed, the present invention is not limited thereto and thereflection pattern 232 may have various structures in which thereflectance of the reflection pattern 232 decreases and thetransmittance or the opening ratio of the reflection pattern 232increases outwardly from the center thereof to its outer areas.

For example, the concentration of the reflection material, for example,the metal or metal oxide in the reflection pattern 232 may decreaseoutwards from the center of the reflection pattern 232 to its outerareas. As a result, by using the backlight unit of the presentinvention, it is possible to prevent the light density fromconcentrating on the area adjacent to the light source due to thedecrease of the reflectance and the increase of the transmittance or theopening ratio.

FIGS. 18 and 19 are cross-sectional views illustrating a configurationof a backlight unit for a display apparatus according to a fifthembodiment of the present invention. The backlight unit of FIGS. 18 and19 may have the same components as the components of the backlight unitof FIGS. 1-17D, which may have been, but not necessarily, referenced byusing certain same reference numerals. A description of the samecomponents of the backlight unit 200 shown in FIGS. 18 to 19 as thecomponents explained by referring to FIGS. 1 to 17D will now be omitted.

Referring to FIG. 18, each reflection pattern 232 of the backlight unitin this example may have a convex shape toward the corresponding lightsource 220. For example, the reflection pattern 232 may have a shapesimilar to a semicircle.

For example, a cross-sectional shape of the reflection pattern 232 mayhave a semicircle shape or an oval shape convexed toward the lightsource 220 as shown in FIG. 18.

The reflection pattern having the convex shape can reflect an incidentlight at various angles. Therefore, by using the reflection pattern 232,it is possible to make the luminance of light to be emitted upwards fromthe resin layer 230 more uniformly by diffusing the light emitted fromthe light source 220 more widely.

The reflection pattern 232 may include the reflection material such asmetal, metal oxide, or the like as described above. For example, thereflection pattern 232 may be formed by forming a pattern on the top ofthe resin layer 230 by an intaglio method and filling the intagliopattern with reflection material.

Alternatively, by printing a film-shaped sheet with the reflectionmaterial or attaching beads or metallic particles to the film-shapedsheet and thereafter, pressing the film onto the resin layer 230, thereflection pattern 232 shown in FIG. 18 may be formed on the top of theresin layer 230.

Meanwhile, a cross-sectional shape of the reflection pattern 232 mayhave various shapes convexed toward the light source 220 in addition toa shape similar to the semicircle shape shown in FIG. 18.

For example, as shown in FIG. 19, the cross-sectional shape of thereflection pattern 232 may have a triangle shape convexed toward thelight source 220. In this case, the reflection pattern 232 may have apyramid shape or a prism shape.

Further, as shown in FIG. 18 or 19, the reflection pattern 232 havingthe shape convexed toward the light source 220 may be disposed to havethe top plane view in the pattern shown in FIGS. 12A to 14.

That is, the reflection pattern 232 may be disposed to have the circularshape or rectangular shape centering on (or off-centered from) theposition where the corresponding light source 220 is formed in thebacklight unit. The reflection pattern 232 may be disposed to have thereflectance decreased and the transmittance or the opening ratioincreased outwards from the center thereof to its outer areas.

For example, in case that the plurality of reflection patterns 232having the shape convexed toward the corresponding light source 220shown in FIG. 18 or 19 are used, a gap between adjacent convexedportions of each reflection pattern 232 may increase outwardly from thecenter of the reflection pattern 232 to its outer areas, therebypreventing the hot spot from being generated due to the concentration oflight on the area adjacent to the light source 220.

Further, although the center of the reflection pattern 232 coincideswith (or substantially coincides with) the center of the light source220 in FIGS. 18 and 19, the center of the reflection pattern 232 may bespaced from the center of the light source 220 in the light emissiondirection by a predetermined gap as described by referring to FIGS. 8 to10.

FIGS. 20A and 20B are cross-sectional views illustrating two differentexamples of a configuration of a backlight unit for a display apparatusaccording to a sixth embodiment of the present invention. Theillustrated backlight unit 200 of FIGS. 20A and 20B can be configured toinclude a plurality of resin layers 230 and 235.

Referring to FIG. 20A, light emitted laterally from the light source 220may be emitted upwards by being diffused by the resin layer 230.Further, the resin layer 230 includes the plurality of scatteringparticles 231 explained by referring to FIG. 4 to scatter or refract thelight upwardly, thereby making the luminance of the light to travelupwards more uniformly.

According to the embodiment of the present invention, a second resinlayer 235 may be disposed on the top of the (first) resin layer 230. Thesecond resin layer 235 can be made of a material similar to or differentfrom the first resin layer 230 and can improve the uniformity of theluminance of the light of the backlight unit 200 by diffusing the lightemitted upward from the first resin layer 230.

The second resin layer 235 can be made of a material having the samerefractive index as the material configuring the first resin layer 230or of a material having a refractive index different therefrom.

For example, when the second resin layer 235 is made of a materialhaving a refractive index higher than that of the first resin layer 230,the second resin layer 235 can more widely diffuse the light emittedfrom the first resin layer 230.

In contrast, when the second resin layer 235 is made of a materialhaving a refractive index lower than that of the first resin layer 230,it is possible to improve reflectivity in which the light emitted fromthe first resin layer 230 is reflected on the bottom of the second resinlayer 235, thereby allowing the light emitted from the light source 220to easily advance along the first resin layer 230.

Meanwhile, the second resin layer 235 may also include a plurality ofscattering particles 236. In this case, the density of the scatteringparticles 236 included in the second layer 235 may be higher than thedensity of scattering particles 231 included in the first resin layer230.

As described above, it is possible to more widely diffuse the lightemitted upward from the first resin layer 230 by including thescattering particles 236 in the second resin layer 235 with a higherdensity, thereby making the luminance of the light emitted from thebacklight unit 200 more uniformly.

According to the embodiments of the present invention, the reflectionpattern 232 explained by referring to FIGS. 7 to 19 above may be formedbetween the first resin layer 230 and the second resin layer 235, and orwithin at least one of the first and second resin layers 230 and 235.

Further, as shown in FIG. 20A, another pattern layer (e.g., pattern 265)may be formed on the top of the second resin layer 235 and the patternlayer formed on the second resin layer 235 may also include a pluralityof patterns.

The pattern 265 on the top of the second resin layer 235 may be areflection pattern that reflects at least part of the light emitted fromthe first resin layer 230. Therefore, it is possible to make theluminance of light emitted from the second resin layer 235 moreuniformly.

For example, when the light traveling upwardly through the second resinlayer 235 is focused on a predetermined part on top of the second resinlayer 235 and is thus observed on the screen with a high luminance, thepattern 265 may be formed in one or more regions corresponding to thepredetermined part(s) of the top of the second resin layer 235.Therefore, according to the invention, it is possible to make theluminance of the light emitted from the backlight unit 200 uniformly byreducing and evenly distributing the luminance of the light in thepredetermined part.

The pattern 265 may be made of titanium dioxide (TiO₂). In this case, apart of the light emitted from the second resin layer 235 may bereflected downwardly and the rest part of the light emitted from thesecond resin layer 235 can be transmitted in the pattern 265. Thepattern 265 can be a light shielding layer/pattern, or anotherreflection pattern 232.

In another example, referring to FIG. 20B, the height of the lightsources 220, 225 may be greater than the thickness of the first resinlayer 230. For instance, a thickness ‘h1’ of the first resin layer 230is smaller than a height ‘h3’ of the light sources 220, 225. As aresult, the first resin layer 230 may cover a lower part of the lightsources 220, 225 and the second resin layer 235 may cover an upper partof the light sources 220, 225.

The first resin layer 230 may be composed of a resin having highadhesive strength. For example, the adhesive strength of the first resinlayer 230 may be higher than that of the second resin layer 235. As aresult, a light emitting surface of the light sources 220, 225 mayadhere to the first resin layer 230 more strongly, and a space betweenthe light emitting surface of the light source 220 (or 225) and thefirst resin layer 230 may not exist or may be minimized.

In one example, the first resin layer 230 may be composed of a siliconresin (or the like) having high adhesive strength, and the second resinlayer 235 may be composed of an acrylic resin or the like.

Further, a refractive index of the first resin layer 230 may be higherthan that of the second resin layer 235. And, the refractive index ofthe first resin layer 230 and the refractive index of the second resinlayer 235 may be within 1.4 to 1.6.

Also, a thickness ‘h2’ of the second resin layer 235 is preferablysmaller than the height ‘h3’ of the light sources 220, 225. Further, thefeatures in the example of FIG. 20A can be provided to the backlightunit of FIG. 20B. For instance, the particles 231 and/or 236 can beprovided in the first and/or second resin layer 230, 235, the pattern265 can be provided on the second resin layer 235, etc.

FIGS. 21 and 22 are diagrams for explaining a positional relationship ofa light source 220 and a reflection layer 240 that are provided in abacklight unit 200 for a display apparatus according to the presentinvention. A description of the same components of the illustratedbacklight unit 200 of FIGS. 21 and 22 as those explained by referring toFIGS. 2 to 20B will now be omitted.

Referring to FIG. 21, as the reflection layer 240 is disposed on theside of the light source 220, a part of light emitted to the side fromthe light source 220 is inputted into the reflection layer 240 to belost.

The loss of the light emitted from the light source 220 decreases theamount of the light that advances by being inputted into the resin layer230. As a result, the amount of light provided from the backlight unit200 to the display panel 100 is decreased, such that the luminance ofthe display picture can be decreased.

According to the embodiment of the present invention, as shown in FIG.22, it is preferable that the light source 220 is positioned above thereflection layer 240. As a result, the light emitted from the lightsource 220 advances along the resin layer 230 and can be emitted upwardwithout being lost by the reflection layer 240.

That is, it is possible to improve the optical efficiency of thebacklight unit 200 by positioning the light emission surface of thelight source 220 above the reflection layer 240.

For example, a support member 215 can be formed between the light source220 and the substrate 210 and the light source 220 can be supported andfixed onto the substrate 210 by the support member 215.

The support member 215 may be made of the same material as any one ofthe substrate 210, the light source 220, and the reflection layer 240.For example, the support member 215 may be formed by extending thesubstrate 210 or by extending a body part of the light source 220 or byextending the reflection layer 240.

The support member 215 can be configured by metal having electricconductivity and for example, can be configured by a metallic materialincluding plumbum (Pb). More specifically, the support member 215 can bea solder pad for soldering the light source 220 onto the substrate 210.

The thickness (b) of the reflection layer 240 can be equal to or smallerthan the thickness (c) of the support member 215. Therefore, the lightsource 220 can be positioned above the reflection layer 240.

Meanwhile, as the thickness (c) of the support member 215, i.e., thesolder pad increases, resistance increases, such that since powersupplied to the light source 220 can be lost, the thickness (c) of thesupport member 215 is preferably equal to or less than 0.14 mm.Therefore, the thickness (b) of the reflection layer 240 can also beequal to or less than 0.14 mm which is the maximum value of thethickness (c) of the support member 215.

Further, as the thickness of (b) of the reflection layer 240 decreases,the light reflectance of the reflection layer 240 can decrease, that is,a part of the light inputted from the light source 220 may betransmitted downward without being reflected at a predeterminedthickness or less.

Therefore, the reflection layer 240 is positioned above the light source220, such that the thickness (b) of the reflection layer 240 can beformed with 0.03 to 0.14 mm in order to reflect most of the lightinputted from the light source 220 while improving the incidentefficiency of the light.

Further, as shown in FIG. 22, a part of the reflection layer 240 can beinserted below the light source 220, more specifically, between thelight source 220 and the substrate 210, thereby more certainly preventthe light emitted from the light source 220 from being lost by thereflection layer 240. For this, the support member 215 can be insertedfrom the end of the light source 220 by a predetermined distance (d).

Meanwhile, as the insertion distance (d) of the support member 215decreases, the size of a part of the reflection layer 240 inserted intothe bottom of the light source decreases to cause the stability of astructure in which the reflection layer 240 is inserted fromdeteriorating. Further, as the insertion distance (d) of the supportmember 215 increases, the light source 220 may unstably be support tothe support member 215.

Accordingly, in order to improve the stability of the insertionstructure of the reflection layer 240 and the support structure of thelight source 220, the insertion distance (d) of the support member 215is preferably in the range of 0.05 to 0.2 mm.

According to yet another embodiment of the present invention, the lightsource 220 can include a head part 22 emitting light in a lateraldirection and a body part having an attaching surface for allowing thelight source 220 to be mounted on the substrate 210, etc. Further, thehead part 22 of the light source 220 can include a light emittingsurface which actually emits light and a non-emitting surface that doesnot emit light on the outer periphery of the light emitting surface.

In this case, the light emitting surface of the head part of the lightsource 220 is preferable positioned above the reflection layer 240.Therefore, it is possible to improve the incident efficiency of thelight by disabling the light emitted from the light source 220 to belost by the reflection layer 240.

According to the embodiments of the invention, the head part 22 and/orthe support member 215 discussed above in connection with FIG. 22 can beprovided in any light source 220 and/or backlight unit 200 according tovarious examples and embodiments of the invention discussed above andbelow.

FIGS. 23 and 24 are diagrams illustrating one embodiment for a structureof a light source 200 provided in a backlight unit 200 according to thepresent invention. FIG. 23 illustrates the structure of the light source220 seen from the side and FIG. 24 illustrates of a structure of thehead part 22 of the light source 220 seen from the front. Any lightsource 220 discussed above and below according to the present inventioncan have the structure of the light source 220 of FIGS. 23 and 24.

Referring to FIG. 23, the light source 220 can be configured to includea light emitting device 321, a mold part 322 having a cavity 323, and aplurality of lead frames 324 and 325. According to the embodiment of thepresent invention, the light emitting device 321 may be or include alight emitting diode (LED) chip and the LED chip may be configured by ablue LED chip or an infrared ray LED chip or by at least one packagetype combining one or more chips of a red LED chip, a green LED chip, ablue LED chip, a yellow green LED chip, and a white LED chip.

Hereinafter, the embodiment of the present invention will be describedby using a case in which the light source 220 is configured to includethe LED chip 321 as the light emitting device for emitting light as anexample.

The LED chip 321 is packaged to the mold part 322 configuring a body ofthe light source 220. For this, the cavity 323 can be formed at one sideof the center of the mold part 322. Meanwhile, the mold part 322 can beinjection-molded with a resin material such as polyphtalamide (PPA),etc. to a press (Cu/Ni/Ag substrate) and the cavity 323 of the mold part322 can serve as a reflection cup. The shape or structure of the moldpart 322 shown in FIG. 23 may be changed and is not limited thereto.

The plurality of lead frames 324 and 325 penetrate in a long axisdirection of the mold part 322. Ends 326 and 327 of the lead frames canbe exposed to the outside. Herein, a long-direction symmetrical axis ofthe mold part 322 is referred to as a long axis and a short-directionsymmetrical axis of the mold part 322 is referred to as a short axis asviewed from the bottom of the cavity 323 where the LED chip 321 isdisposed.

Semiconductor devices such as a light receiving device, a protectiondevice, etc. may selectively be mounted on the lead frames 324 and 325in the cavity 323 in addition to the LED chip 321. For example, theprotection device such as a zener diode, etc. for protecting the LEDchip 321 from static electricity, etc. (e.g., ESD: electro staticdischarge) may be mounted on the lead frames 324 and 325 in addition tothe LED chip 321.

The LED chip 321 adheres to any one lead frame 325 positioned on thebottom of the cavity 323 and thereafter, the LED chip 321 can beconnected by wire bonding or flip chip bonding.

Further, after the LED chip 321 is connected, a resin material is moldedto the mounting region in the cavity 323. The resin material hereincludes a silicon or epoxy material. Phosphor may selectively be addedto this resin material. The resin material can be formed in any oneshape of a flat shape in which the surface of the resin material ismolded with the same height as the top of the cavity 323, a concave lensshape concaved to the top of the cavity 232, and a convex lens shapeconvexed to the top of the cavity 323.

At least one side of the cavity 323 is inclined and this side may serveas a reflection surface for selectively reflecting an impinging light ora reflection layer. The cavity 323 may have a polygonal exterior shapeand may have shapes other than the polygonal shape.

Referring to FIG. 24, the head part 22 of the light source 220 which isa part emitting the light can include a light emitting surface(displayed by an oblique line) actually emitting the light and anon-emitting surface not emitting the light, which is a part other thanthe light emitting surface.

More specifically, the light emitting surface of the head part 22 of thelight source 220, which emits the light is formed by the mold part 322and can be defined by the cavity 323 disposed in the LED chip 321. Forexample, the LED chip 321 is disposed in the cavity 323 of the mold part322, such that the light emitted from the LED chip 321 can be emittedthrough the light emitting surface surrounded by the mold part 322.Further, the non-emitting surface of the head part 22 of the lightsource 220 may be a part (not displayed by the oblique line) where themold part 322 is formed and the light is not emitted.

Further, as shown in FIG. 24, the light emitting surface of the headpart 22 of the light source 220 has a shape in which a horizontal lengthis longer than a vertical length. However, the shape of the lightemitting surface of the head part 22 is not limited to the shape shownin FIG. 24. For example, the light emitting surface of the light source220 may have a rectangular shape.

In addition, the non-emitting surface of the head part 22 that does notemit the light may be positioned at upper, lower, left, or right side ofthe light emitting surface of the head part 22 of the light source 220.

Meanwhile, the ends of 326 and 327 of the lead frames 324 and 325 extendto the outer frame of the mold part 322 to be firstly formed andsecondly formed in one groove of the mold part 322 to be disposed infirst and second lead electrodes 328 and 329. Herein, the number offabrication times may be changed and is not limited thereto.

The first and second lead electrodes 328 and 329 of the lead frames 324and 325 can be formed to be received in grooves formed at both sides ofthe bottom of the mold part 322. Further, the first and second leadelectrodes 328 and 329 are formed with a plate structure having apredetermined shape and may be formed with a shape in which solderbonding is easy in surface mounting.

FIG. 25 is a cross-sectional view illustrating a configuration of abacklight unit according to a seventh embodiment of the presentinvention. Description of the same components of the backlight unit 200shown in FIG. 25 as those explained by referring to FIGS. 1 to 24 willnow be omitted.

A pattern 241 for allowing the light emitted from the light source 220to easily advance to the adjacent light source 225 may be formed in thereflection layer 240. For example, referring to FIG. 25, the pattern 241formed on the top of the reflection layer 240 may include a plurality ofprotrusions, and the light emitted from the light source 220 andinputted into the plurality of protrusions of the pattern 241 may bescattered or refracted in the advance direction.

Meanwhile, as shown in FIG. 25, the density of the protrusions (241)formed in the reflection layer 240 may increase outwardly as theprotrusions (241) are separated from the light source 220, that is,close to the adjacent light source 225 (which is also the light source220). For example, more protrusions may be formed between two adjacentlight sources 220 and 225 as you move from the left to the rightdirection in FIG. 25. Accordingly, it is possible to prevent theluminance of the light emitted upwardly from a region remotely separatedfrom the light source 220, e.g., a region close to the adjacent lightsource 225 from being reduced, thereby maintaining the luminance of thelight provided from the backlight unit 200 more uniformly.

Further, the protrusions of the pattern 241 may be made of the samematerial as the reflection layer 240. In this case, the protrusion ofthe pattern 241 can be formed by processing the top of the reflectionlayer 240.

As a variation, the protrusions of the pattern 241 may be made of amaterial different from the reflection layer 240, for example, theprotrusions of the pattern 241 may be formed on the top of thereflection layer 240 by printing the pattern shown in FIG. 25.

Meanwhile, the shape of the protrusions of the pattern 241 is notlimited to the shape shown in FIG. 25 and for example, may have variousshapes such as a prism shape, etc.

For example, as shown in FIG. 26, a pattern 241 may be formed on thereflection layer 240 and may have an engraving shape.

FIG. 27 is a cross-sectional view of another embodiment of a shape of apattern 241 formed on the reflection layer 240 and the pattern 241 maybe formed on only a partial region of the reflection layer 240.

Referring to FIG. 27, the reflection layer 240 may include a firstregional where the engraving or embossing pattern 241 is not formed anda second region a2 where the pattern 241 is formed as described above.

Meanwhile, the first regional where the pattern 241 is not formed may bedisposed more adjacent to the light source 220 that emits the lightbetween the first and second regions a1 and a2.

As described above, the first regional where the pattern 241 is notformed is disposed adjacent to the light source 220, and the secondregion a2 where the pattern 241 is formed is disposed away from thelight source 220 so as to efficiently transmit the light emitted fromthe light source 220 to a region far away from the light source 220.

Further, in the region far away from the light source, for example, thesecond region a2 where the pattern 241 is formed, the light emitted fromthe light source 220 is scattered by the pattern 241 and is therebyemitted upward, thereby preventing the luminance of the light from beingreduced in the second region a2.

Further, as described above and shown in FIG. 27, in the second regiona2 of the reflection layer 240, the density of the pattern 241 mayincrease in the light emission direction (e.g., the arrows shown inFIGS. 25-27) of the corresponding light source 220, e.g., the density ofthe pattern 241 increases as one moves farther away from thecorresponding light source 220.

FIG. 28 illustrates an embodiment of an arrangement of patterns formedon the reflection layer and schematically illustrates the arrangement ofa plurality of patterns 241 formed on the reflection layer 240 on thebasis of the position of the light source 220.

Referring to FIG. 28, the width w of the region where the plurality ofpatterns 241 are formed may increase in the light emission direction, asone moves farther away from the light source 220 emitting the light tothe reflection layer 240.

That is, the light emitted from the light source 220 may propagate whilegradually being dispersed at a predetermined orientation angle, e.g.,approximately 120 degrees primarily in a first direction (indicated byan arrow). Therefore, the width w of the region where the plurality ofpatterns 241 are formed may also increase in the light emissiondirection of the light source 220.

FIG. 29 illustrates another embodiment of arrangement of the patterns241 formed on the reflection layer 240.

Referring to FIG. 29, the backlight unit 200 includes two or more lightsources 220 and 221 that emit the light in different directions, and thepatterns 241 arranged as shown in FIG. 29 may be formed on thereflection layer 240 to correspond to the positions of the light sources220 and 221.

That is, the patterns 241 are not formed in the first region of thelight source 220 immediately adjacent to the light source 220 in respectto the plurality of light sources 220 and 221 while the plurality ofpatterns 241 may be formed in the second region farther away from thecorresponding light source 220. Here the first region is between thesecond region and the corresponding light source 220.

Meanwhile, for each light source 220, 221, the density and/or width W ofthe corresponding patterns 241 increases in the light emission directionof the corresponding light source.

According to another embodiment of the present invention, the backlightunit 200 can include two or more light sources that emit light indifferent directions. For example, FIG. 30 is a cross-sectional viewillustrating an embodiment for a structure of a plurality of lightsources provided in a backlight unit 200 according to the invention. Asshown in FIG. 30, the first light source 220 and the second light source225 of the plurality of light sources provided in the backlight unit 200may emit light in different directions.

For example, the first light source 220 emits the light in a lateraldirection. For this, the first light source 220 can be configured byusing the side view-type LED package. Meanwhile, the second light source225 emits the light in an upward direction. For this, the second lightsource 225 can be configured by using the top view-type LED package. Inthe backlight unit 220, the plurality of light sources 220 can bealternatively the side view-type LED package and side view-type LEDpackage.

As described above, according to the invention it is possible to preventlight from being focused on a predetermined region or being weakened, byconfiguring the backlight unit 200 by combining two or more lightsources that emit the light in different directions. As a result, thebacklight unit 200 can provide light having uniform luminance to thedisplay panel 100.

Meanwhile, in FIG. 30, the embodiment of the present invention isdescribed by using a case in which the first light source 220 emittingthe light in the lateral direction and the second light source 225emitting the light in the upward direction are disposed adjacent to eachother as an example, but the present invention is not limited thereto.For example, within the backlight unit 200, two or more side view-typelight sources may be disposed adjacent to each other, two or more topview-type light sources may be disposed adjacent to each other, or anycombination thereof or any arrangement of thereof.

Hereinafter, various arrangements of the light sources 220 and 221 willbe described in detail with reference to FIGS. 31 to 35.

FIG. 31 is a plan view illustrating a front shape of a backlight unitaccording to an embodiment of the present invention, and illustrates anembodiment for a layout structure of a plurality of light sourcesprovided in the backlight unit 200 according to the invention. Any lightsource 220 discussed above in connection with FIGS. 1 to 30 can be thelight source (e.g., 220, 221, 222, 224, etc.) of FIGS. 31 to 35. Thevarious arrangements of the light sources 220 of FIGS. 31 to 35 can beused in the display module 20 or the like.

Referring to FIG. 31, the plurality of light sources 220 and 221included in the backlight unit 200 may be disposed by being divided intoa plurality of arrays, for example, a first light source array A1 and asecond light source array A2.

Each of the first light source array A1 and the second light sourcearray A2 includes a plurality of light source lines constituting lightsources. For example, the first light source array A1 is composed ofmultiples lines L1, L1, . . . of the light sources 220, and the secondlight source array A2 is composed of multiple lines L2, L2, . . . of thelight sources 220. The light source lines included in the first lightsource array A1 and the light source lines included in the second lightsource array A2 may be alternately disposed each other, to correspond tothe displaying region of the display panel 100.

According to one embodiment of the present invention, the first lightsource array A1 may include odd number-th light source lines from thetop among the plurality of light source lines, and the second lightsource array A2 may include even number-th light source lines from thetop.

For example, as shown in FIG. 31, a first light source line L1 includedin the first light source array A1 and a second light source line L2included in the second light source array A2 are disposed adjacent toeach other, and the first light source line L1 and the second lightsource line L2 are alternately disposed each other to configure thebacklight unit 200. As such, the light sources of the backlight unit 200are disposed in a matrix configuration.

Further, the light sources 220 included in the first light source arrayA1 and the light sources 221 included in the second light source arrayA2 may emit light in the same direction or in different directions. Forexample, referring to FIG. 32, the backlight unit 200 may include two ormore light sources that emit light in different directions. That is, thelight sources 220 included in the first light source array A1 and thelight sources 221 included in the second light source array A2 may emitlight in different directions from each other. For this, a directionwhich the light emitting surfaces of the light sources 220 included inthe first light source array A1 face may be different from a directionwhich light emitting surfaces of the light sources 221 included in thesecond light source array A2 face.

More specifically, the light emitting surface of each first light source220 included in the first light source array A1 and the light emittingsurface of each second light source 221 included in the second lightsource array A2 may face in different directions. Therefore, as shown inFIG. 32, the first light sources 220 included in the first light sourcearray A1 and the second light sources 221 included in the second lightsource array A2 may emit light in different directions, e.g., inopposite directions. In this case, the light sources provided in thebacklight unit 200 can emit the light in the lateral direction. Forthis, the light sources can be configured by using the side view-typeLED packages.

Meanwhile, as shown in FIG. 32, the plurality of light sources providedin the backlight unit 200 can be disposed while forming two or morelines, and two or more light sources disposed on the same line can emitthe light in the same direction.

For example, light sources right/left adjacent to the first light source220 can also emit the light in the same direction as the first lightsource 220, e.g., in the direction opposite to the x-axis direction, andlight sources right/left adjacent to the second light source 221 canalso emit the light in the same direction as the second light source221, e.g., in the x-axis direction.

As described above, by providing the light emitting directions of thelight sources disposed adjacent to each other in the y-axis direction,for example, the first light source 220 and the second light source 221to be opposite to each other, the present invention makes it possible toprevent the luminance of the light from being focused or being weakenedin a predetermined region of the backlight unit 200.

For example, as the light emitted from the first light source 220travels towards the adjacent light source, the light may be weakened. Asa result, as the light is remotely separated from the first light source220, the luminance of the light emitted in the direction of the displaypanel 100 may be weakened.

Accordingly, as shown in FIG. 32, by making the light emittingdirections of the first light source 220 and the second light source 221opposite to each other, the first light source 220 and the second lightsource 221 can complementarily prevent the luminance of the light frombeing focused in the region adjacent to the light source and theluminance of the light from being weakened in the region remotelyseparated from the light source, thereby maintaining the luminance ofthe light emitted from the backlight unit 200 uniformly.

Further, in the first light source lines L1 included in the first lightsource array A1 and the second light source lines L2 included in thesecond light source array A2, right and left positions of the lightsources do not coincide with each other but cross each other. As aresult, it is possible to improve further the uniformity of the lightemitted from the backlight unit 200. For example, as shown in FIG. 32,the second light sources 221 included in the second light source arrayA2 may be disposed adjacent to the first light sources 220 included inthe first light source array A1 in a diagonal direction.

Referring to FIG. 33, the light sources in two or more light sourcelines in the first light source array A1 may line up vertically orsubstantially vertically, the light sources in two more light sources inthe second light source array A2 may line up vertically orsubstantially. Further, the first light source line L1 and the adjacentsecond light source line L2 may be separated from each other by apredetermined distance d1.

That is, the first light sources 220 included in the first light sourcearray A1 and the second light sources 221 included in the second lightsource array A2 may be separated from each other by the predetermineddistance d1 on the basis of a y-axis direction vertical to an x-axis inwhich the light is emitted.

As the distance d1 between the first light and second light source linesL1 and L2 increases, a region which the light emitted from the firstlight source 220 or the second light source 221 cannot reach may begenerated and thus, the luminance of the light in the region may beweakened.

Meanwhile, as the distance d1 between the first light and second lightsource lines L1 and L2 decreases, the light emitted from the first lightsources 220 and the light emitted from the second light sources 221 mayinterfere with each other. In this case, the division driving efficiencyof the light sources may be deteriorated.

Accordingly, in order to make the luminance of the light emitted fromthe backlight unit 200 uniform while reducing the interference of thelight resources, the distance d1 of the light source lines, for example,the first and second light source lines L1 and L2 (220 and 221), whichare adjacent in the same direction crossing the direction in which thelight is emitted may be, e.g., 5 to 22 mm.

Further, the third light source 222 is included in the first lightsource line of the first light source array A1 and disposed adjacent tothe first light source 220 in the x-axis direction, and the first lightsource 220 and the third light source 222 can be spaced from each otherby a predetermined distance d2.

Further, a light orientation angle θ from the light source and a lightorientation angle θ′ in the resin layer 230 can have a relationshipshown in Equation 1 by the Snell's law.

$\begin{matrix}{\frac{n\; 1}{n\; 2} = \frac{\sin\mspace{11mu}\theta^{\prime}}{\sin\mspace{11mu}\theta}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Meanwhile, when a part that emits the light from the light source is anair layer (refractive index n1 is ‘1’) and an orientation angle θ of thelight emitted from the light source is generally 60 degrees, the lightorientation angle θ′ in the resin layer 230 can have a value shown inEquation 2 in accordance with Equation 1.

$\begin{matrix}{{\sin\mspace{11mu}\theta^{\prime}} = \frac{\sin\mspace{11mu} 60{^\circ}}{n\; 2}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

Further, when the resin layer 230 is made of an acrylic resin type suchas polymethyl methacrylate (PMMA), the resin layer 230 has a refractiveindex of approximately 1.5. Therefore, the light orientation angle θ′ inthe resin layer 230 can be approximately 35.5 degrees in accordance withEquation 2.

As described by referring to Equations 1 and 2, the light orientationangle θ′ of the light emitted from the light source in the resin layer230 can be less than 45 degrees. As a result, a range in which the lightemitted from the light source advances in the y-axis direction can besmaller than a range in which the light advances in the x-axisdirection.

Accordingly, the distance d1 between two light sources adjacent to eachother in the direction crossing the light emitting direction, e.g., thefirst light source 220 and the second light source 221 can be smallerthan the distance d2 between two light sources adjacent to each other inthe light emitting direction, e.g., the first light source 220 and thethird light source 222, thereby maintaining the luminance of the lightemitted from the backlight unit 200 uniformly.

Meanwhile, by considering the distance d1 between the light source linesadjacent to each other, which has the above-mentioned range, thedistance d2 between two light sources adjacent to each other in thelight emitting direction, e.g., the first light source 220 and the thirdlight source 222, can be 9 to 27 mm in order to maintain the luminanceof the light emitted from the backlight unit 200 uniformly whilereducing an interference between the light sources.

Referring to FIG. 33, the second light source 221 included in the secondlight source array A2 may be disposed to correspond to a positionbetween the first light source 220 and the third light source 222adjacent to each other, which are included in the first light sourcearray A1 in a diagonal direction.

That is, the second light source 221 is disposed adjacent to the firstlight source 220 and the third light source 222 in the y-axis directionand can be disposed on a straight line l passing between the first lightsource 220 and the third light source 222.

In this case, a distance d3 between the straight line l on which thesecond light source 221 is disposed and the first light source 220 canbe larger than a distance d4 between the straight line l and the thirdlight source 222.

The light emitted from the second light source 221 advances in adirection opposite to the light emitting direction of the third lightsource 222 to thereby weakening or distributing the luminance of thelight emitted in the direction of the display panel 100 in a regionadjacent to the third light source 222.

Therefore, by disposing the second light source 221 closer to the thirdlight source 222 than to the first light source 220, it is possible tocompensate the decrease in the luminance of the light in the regionadjacent to the third light source 222 by using the luminance of thelight focused on the region adjacent to the second light source 221.

Meanwhile, at least one of the plurality of light sources 220 providedin the backlight unit 200 may emit the light more towards a horizontaldirection, that is, in a direction slanted from the x-axis direction.

For example, referring to FIG. 34, directions in which the lightemission surfaces of the light sources 220 and 221 face may be formedobliquely upwards or downwards at a predetermined angle on the basis ofthe x-axis direction.

In another variation as shown in FIG. 35, the light sources in the lightsource lines can be staggered with respect to each other for thebacklight unit 200. For example, the light sources in the lines L1, L3and L2 of the first light source array A1 can be staggered with respectto the light sources in the lines L2, L1 and L3 of the second lightsource array A2.

Therefore, the lines L1, L3, and L2 included in the first light sourcearray A1 and the lines L2, L1, and L3 included in the second lightsource array A2 may be alternatively disposed.

As such, the light sources 220, 221 and 224 may form a diagonal or slantline while the light sources in the lines L1 and L1 may correspond toeach other. Other variations are possible. Preferably the light sources220, 221, 224, 222, etc. are all basically the same light sources, butmay have different light emitting directions; however, these lightsources may have other varying characteristics if desired and may be ofdifferent type, size, orientation, etc.

FIGS. 36 to 39 are plan views illustrating various first examples of astructure of a reflection layer that is provided in a backlight unitaccording to an embodiment of the present invention.

Referring to FIG. 36, the reflection layer 240 provided in the backlightunit 200 according to the embodiments of the present invention can havetwo or more different portions having respectively differentreflectances. For example, the reflection layer 240 can be configured tohave different reflectances depending on a position where the reflectionlayer 240 is formed. The reflection layer 240 of FIG. 36 can be used asthe reflection layer 240 discussed above and below in any otherembodiment or example.

For example, the reflection layer 240 can include a first reflectionlayer (or portion) 242 and a second reflection layer (or portion) 243that have different reflectances. The reflection layer 240 can beconfigured by alternatively disposing the first and second reflectionlayers 242 and 243 having different reflectances as shown.

For example, the reflectances of the first and second reflection layers242 and 243 can be implemented to be different by forming the first andsecond reflection layers 242 and 243 by reflection sheets made ofdifferent materials or by adding a predetermined material to any one ofthe first and second reflection layers 242 and 243 formed by the samereflection sheet or processing the surface.

According to another example of the present invention, the first andsecond reflection layers 242 and 243 may be configured by one reflectionsheet which is not physically separated. In this case, the first andsecond reflection layers 242 and 243 having different reflectances maybe formed by forming a pattern for selectively adjusting the reflectancein at least a part of the reflection sheet.

As a result, it is possible to adjust the reflectance by forming thepattern in at least one area of an area of the reflection layer 240corresponding to the first reflection layer 242 and an area of thereflection layer 240 corresponding to the second reflection layer 243.For example, by forming the pattern in an area of the reflection layer240 configured by one sheet corresponding to the second reflection layer243 shown in FIG. 36, it is possible to adjust the reflectance of thecorresponding area.

More specifically, protruded patterns for diffusing light may be formedon the top of the area of the reflection layer 240 corresponding to thesecond reflection layer 243, thereby reducing the reflectance of thearea corresponding to the second reflection layer 243. In this case, alight diffusion effect can be improved in the area of the reflectionlayer 240 corresponding to the second reflection layer 243. As a result,light emitted from the light source 220 can be more uniformly diffusedto an area disposed in the adjacent light source 222.

A surface roughness of the first reflection layer 242 is different froma surface roughness of the second reflection layer 243. For example, thesurface roughness of the first reflection layer 242 is higher than thesurface roughness of the second reflection layer 243. As a result, areflectance of the second reflection layer 243 is lower than areflectance of the first reflection layer 242.

Meanwhile, the first reflection layer 242 of the first and secondreflection layers 242 and 243 adjacent to the light sources 220, 221,and 222 can be configured by a specular reflection sheet on the basis ofthe light emitting direction and the second reflection layer 243 can beconfigured by a diffuse reflection sheet. Incident light is reflected onthe smooth surface of the specular reflection sheet, such that anincident angle and a reflection angle can be the same. Therefore, thefirst reflection layer 242 allows light obliquely inputted from thelight sources 220, 221, and 222 to advance in a direction orienting theadjacent light source by reflecting the light at the reflection angleequal to the incident angle.

Meanwhile, in the diffuse reflection sheet, the incident light can beobserved as reflected and diffused at various angles due to the diffusedreflection generated on a rough surface with unevenness. Therefore, thesecond reflection layer 243 can propagate the light upwards by diffusingthe light advancing from the light sources 220, 221, and 222.

According to one embodiment of the present invention, the secondreflection layer 243 configured by, e.g., the diffuse reflection sheetcan be formed by forming unevenness thereon by processing the surface ofthe reflection sheet or by applying or adding a diffuse reflectionmaterial, e.g., titanium dioxide (TiO2) with a predetermined density.

In this case, the reflectance of the first reflection layer 242 is setto be higher than the reflectance of the second reflection layer 243.Therefore, as described above, the light inputted from the light sources220, 221, and 222 is specularly reflected at the same reflection anglein the first reflection layer 242 and the diffuse reflection isgenerated, such that the light can be emitted upward in the secondreflection layer 243.

As described above, the light emitted from the light sources 220, 221,and 222 can effectively advance towards the adjacent light source byconfiguring the first reflection layer 242 adjacent to the light sources220, 221, and 222 by the specular reflection sheet having a highreflectance on the basis of the light emitting direction. Therefore, itis possible to prevent the luminance of the light from being focused inthe region immediately adjacent to the light sources 220, 221, and 222and to prevent the luminance of the light from decreasing in the regionremotely spaced from the light sources 220, 221, and 222.

As described above, the advancing light can effectively be emitted tothe display panel 100 by configuring the second reflection layer 243more remotely spaced from the light sources 220, 221, and 222 with thediffuse reflection sheet having a comparatively low reflectance on thebasis of the light emitting direction. Therefore, according to theinvention, it is possible to prevent the luminance of the light fromdecreasing in the region remotely spaced from the light sources 220,221, and 222 by compensating for the luminance reduced as the lightpropagates once it is emitted from the light sources 220, 221, and 222.

Meanwhile, a specular reflection sheet constituting the first reflectionlayer 242 specularly reflects the light emitted from the light sources220, 221, and 222 and propagates the light in the direction of theadjacent light source, and emits part of the incident light in thedirection of the display panel 100 by reflecting or scattering the partof the incident light upwards.

The diffusion reflection sheet constituting the second reflection layer243 may be manufactured by processing the surface of a sheet made of thesame material as the specular reflection sheet or by forming theplurality of patterns that are protruded on the surface thereof.

According to the embodiment of the present invention, the luminance ofthe light in the region adjacent to the light sources 220, 221, and 222and the luminance of the light in the region remotely spaced from thelight sources 220, 221, and 222 can similarly be adjusted. Therefore, itpossible to provide the uniform light luminance to the display panel 100throughout the entire region of the backlight unit 200.

Preferably the width w1 of the first reflection layer 242 adjacent tothe light sources 220, 221, and 222 can be larger than the width w2 ofthe second reflection layer 243 on the basis of the light emittingdirection in order to allow the light emitted from the light sources220, 221, and 222 to propagate properly towards the region where theadjacent light source is disposed. However, the width w1 may be the sameas or less than the width W2 but the reflectances of the first andsecond reflection layers 242 and 243 may then vary as needed to achievethe desired effect.

Meanwhile, as the width w1 of the first reflection layer 242 decreases,the progressiveness of the light emitted from the light sources 220,221, and 222 can be deteriorated. As a result, the luminance of thelight in the region remotely spaced from the light sources 220, 221, and222 can be decreased.

Further, when the width w1 of the first reflection layer 242 is stilllarger than the width w2 of the second reflection layer 243, the lightcan be focused in the region remotely spaced from the light sources 220,221, and 222. For example, the luminance of the light in the middleregion between the two adjacent light sources 220 and 222 can be lowerthan that in the region remotely spaced from the light sources 220, 221,and 222.

Accordingly, the light emitted from the light sources 220, 221, and 222effectively advances towards the region where the adjacent light sourceis disposed and is emitted upwardly so as to provide the light having auniform luminance to the display panel 100 throughout the entire regionof the backlight unit 200. For this, the width w1 of the firstreflection layer 242 can be 1.1 times to 1.6 times larger than the widthw2 of the second reflection layer 243.

Referring to FIG. 36, the first light source 220 and the second lightsource 221 that are disposed adjacent to each other in the y-axisdirection can be disposed at a position not overlapped with the firstreflection layer 242, that is, outside of the region where the firstreflection layer 242 is formed.

Further, the third light source 222 and the second light source 221 thatare adjacent to the first light source 220 in the x-axis direction canbe disposed in the region where the second reflection layer 243 isformed.

For example, holes or indentations (not shown) into which the secondlight source 221 and the third light source 222 can be inserted can beformed in the second reflection layer 243. As a result, the second andthird light sources 221 and 222 mounted on the substrate 210 disposedbelow the second reflection layer 243 protrude upwardly through the holeof the second reflection layer 243 to thereby emit the light in thelateral direction.

Meanwhile, since the positions of the light sources 220, 221, and 222shown in FIG. 36 are just one embodiment of the present invention, thepositional relationship between the light sources 220, 221, and 222, andthe first and second reflection layers 242 and 243 may vary.

For example, referring to FIG. 37, each of the light sources 220 and221, and 222 may be formed along a boundary between the first reflectionlayer 242 and the second reflection layer 243.

In another example, as shown in FIG. 38, the light sources 220, 221, and222 may be positioned all within the region where the first reflectionlayer 242 is formed. And these light sources can be touching theboundary between the first and second reflection layer 242 and 243.

In still another example, referring to FIG. 39, the light sources 220and 221, and 222 may be formed all within the region where the firstreflection layer 242 is formed while being spaced from the boundarybetween the first reflection layer 242 and the second reflection layer243.

According to the embodiment of the present invention, a gradation areawhere the light reflectance gradually increases or decreases may beformed at a boundary between the first and second reflection layers 242and 243 that have different reflectances

For example, the light reflectance may gradually decrease from one sideof the gradation area adjacent to the first reflection layer 242 to theother side adjacent to the second reflection layer 243.

Meanwhile, the pattern 241 formed on the reflection layer 240 explainedby referring to FIGS. 25 to 29 may be formed on both the firstreflection layer 242 and the second reflection layer 243 or any onelayer of them.

For example, the pattern 241 may be formed on the second reflectionlayer 243 further separated from the light source 220 on the basis ofthe direction (indicated by the arrow in FIG. 36) in which the lighttravels between the first and second reflection layers 242 and 243.Therefore, it is possible to prevent the luminance of the light sourcefrom being reduced in an area far away from the light source 220.

FIG. 40 is a plan view illustrating a second example for a structure ofa reflection layer provided in a backlight unit according to the presentinvention. Description of the same components of the illustratedreflection layer 240 as those explained by referring to FIGS. 36 to 39will now be omitted.

Referring to FIG. 40, the reflectance of the second reflection layer 243can gradually increase or decrease depending on the position of thesecond reflection layer 243.

According to the embodiment of the present invention, the reflectance ofthe second reflection layer 243 can gradually decrease in the direction(x-axis direction) in which the light is emitted from the light source221.

For example, the reflectance of the second reflection layer 243 has thehighest reflectance, i.e., the reflectance similar to the reflectance ofthe first reflection layer 242 at or around the boundary between thesecond reflection layer 243 and the first reflection layer 242. Thereflectance of the second reflection layer 243 can gradually decrease inthe x-axis direction as one moves away from the first reflection layer242.

As described above, the reflectance at or around the boundary betweenthe first reflection 242 and the second reflection layer 243 can gentlybe changed by configuring the reflectance of the second reflection layer243 and as a result, it is possible to reduce or avoid a difference ofthe light luminance generated due to a rapid change in the reflectanceat the boundary.

The second reflection layer 243 can be configured by the diffusereflection sheet as described above. In this case, a diffuse reflectionmaterial may be formed in the second reflection layer 243. Therefore, itis possible to gradually decrease or increase the reflectance of thesecond reflection layer 243 depending on the position by graduallyincreasing or decreasing the concentration of the diffuse reflectionmaterial formed in the second reflection layer 243.

For example, as shown in FIG. 40, the concentration of titanium dioxide(TiO₂) which is one example of the diffuse reflection material formed inthe second reflection layer 243 can gradually be increased in thedirection (e.g., x-axis direction) in which the light is emitted fromthe light source 221. Therefore, the reflectance of the secondreflection layer 243 can gradually be decreased effectively.

FIG. 41 is a plan view illustrating a third example for a structure of areflection layer that is provided in a backlight unit according to thepresent invention. This example may be identical to that shown in FIG.40, except that the second reflection layer 243 is now composed ofdifferently divided portions having different reflectances.

Referring to FIG. 41, the second reflection layer 243 can include aplurality of first reflection units 244 and a plurality of secondreflection units 248 having different a reflectance from that of thefirst reflection unit 244, which are alternatively and repetitivelydisposed (not shown). In another example as shown in FIG. 41, the secondreflection layer 243 can be composed of a plurality of first reflectionunits 244, 245, 246, and 247 and a plurality of second reflection units248 alternatively disposed.

In this case, widths g1, g2, g3, and g4 of the first reflection units244, 245, 246, and 247 included in the second reflection layer 243 cangradually increase on the basis of the direction (e.g., x-axisdirection) in which the light is emitted from the light source 221.

Meanwhile, the reflectance of the first reflection units 244, 245, 246,and 247 can be smaller than the reflectance of the second reflectionunit 248 and the reflectance of the second reflection unit 248 can beequal to the reflectance of the first reflection layer 242. That is, thesecond reflection unit 248 can be included in the first reflection layer242.

For example, the second reflection unit 248 included in the firstreflection layer 242 and the second reflection layer 243 can beconfigured by the above-mentioned specular reflection sheet, and thefirst reflection units 244, 245, 246, and 247 included in the secondreflection layer 243 can be configured by the diffuse reflection sheet.

Therefore, the average reflectance of the second reflection layer 243can be lower than the reflectance of the first reflection layer 242 tothereby provide a more uniform luminance of the light throughout theentire region of the backlight unit 200.

Meanwhile, as shown in FIG. 41, as the widths g1, g2, g3, and g4 of thefirst reflection units 244, 245, 246, and 247 are increased in theX-axis direction as the first reflection units are positioned fartherfrom the light source 221, the reflectance of the second reflectionlayer 243 can be gradually decreased like the example shown in FIG. 40.

Therefore, the reflection at or near the boundary between the firstreflection layer 242 and the second reflection layer 243 can be gentlychanged, such that it is possible to reduce the difference in theluminance of the light generated due to the rapid change in thereflectance at the boundary.

In the above description, the embodiments of the present invention havebeen described by using a case in which the reflectance of the secondreflection layer 243 is changed depending on its position while thefirst reflection layer 242 has a uniform reflectance with reference toFIGS. 40 and 41, but the present invention is not limited thereto.

That is, in another example, while the second reflection layer 243 hasthe uniform reflectance, the reflectance of the first reflection layer242 may be changed depending on its position, such that the reflectanceat the boundary between the first and second reflection layers 242 and243 can be gently changed. In still another example, the reflectance ofeach of the first and second reflection layers 242 and 243 may bechanged depending on their positions.

FIG. 42 is a plan view illustrating a fourth embodiment of the structureof a reflection layer provided in a backlight unit according to thepresent invention. A description of the same components of theillustrated reflection layer 240 shown in FIG. 42 as those explained byreferring to FIGS. 36 to 41 will now be omitted.

Referring to FIG. 42, a plurality of reflection portions 244, 245, and246 may be formed in a part of the region where the first reflectionlayer 242 is formed, which is adjacent to the second reflection layer243.

The plurality of reflection portions 244, 245, and 246 may extend in thedirection in which the light is emitted from the light source 221, thatis, the x-axis direction in this example. The plurality of reflectionportions 244, 245, and 246 may have different sizes, shapes, and/orreflectances and may be made of different materials.

The reflectances of the reflection portions 244, 245, and 246 may besmaller than the reflectance of the first reflection layer 242 and maybe equal to the reflectance of the second reflection layer 243.

For example, the reflection portions 244, 245, and 246 and the secondreflection layer 243 may be constituted by the diffusion reflectionsheets.

The positions of the light sources 221 and 226 shown in FIGS. 40 to 42are just one example of the present invention. As such, the positions ofthe light sources 221 and 226 may vary as described by referring toFIGS. 36 to 39.

FIG. 43 is a cross-sectional view illustrating a configuration of abacklight unit according to yet another embodiment of the presentinvention.

Referring to FIG. 43, the first layer 210, the plurality of lightsources 220 formed on the first layer 210, the second layer 230 coveringthe plurality of light sources 220, and the reflection layer 240 thatare described with reference to FIGS. 3 to 42 can configure one opticalassembly 10, and one backlight unit 200 can be configured by disposing aplurality of such optical assemblies 10 adjacent to each other.

Meanwhile, in the case of the plurality of optical assemblies 10provided in the backlight unit 200, N and M (N or M represents a naturalnumber of 1 or more) optical assemblies can be disposed as a matrix typein the x-axis direction and the y-axis direction, respectively.

As shown in FIG. 43, in the backlight unit 200, twenty-one (21) opticalassemblies 10 can be disposed in 7×3 matrix. However, since theconfiguration shown in FIG. 43 is just one example for describing thebacklight unit according to the present invention, the present inventionis not limited thereto and can be changed depending on a screen size ofthe display apparatus, etc.

For example, in the case of a display apparatus having a 47-inch size,the backlight unit 200 can be configured by disposing 240 opticalassemblies 10 in 24×10 matrix.

Each of the optical assemblies 10 can be fabricated as an independentassembly and the optical assemblies 10 are adjacent to each other toform a module-type backlight unit. The module-type backlight unit as abacklight means can provide the light to the display panel 100.

As described above, the backlight unit 200 can be driven by a fulldriving scheme or a partial driving scheme such as local dimming,impulsive, etc. The driving scheme of the backlight unit 200 can bevariously changed depending on the circuit design and is not limitedthereto. As a result, in the embodiment, a color contrast ratio isincreased and images for a bright part and a dark part can be clearlyexpressed, such that an image quality is improved.

For example, the backlight unit 200 operates by being divided into aplurality of division driving regions, and the luminance of the darkpart is increased and the luminance of the bright part is decreased bylinking the luminance of the division driving region with the luminanceof a picture signal, thereby improving a contrast ratio and definitionof the display apparatuses.

For example, it is possible to emit the light upwardly by independentlydriving only some of the plurality of optical assemblies 10 shown inFIG. 43. For this, the light sources 220 included in each of the opticalassemblies 10 can be independently controlled.

Meanwhile, a region of the display panel 100 corresponding to oneoptical assembly 10 can be divided into two or more blocks. The displaypanel 100 and the backlight unit 200 may be separately driven by theunit of a block.

According to the embodiment of the present invention, the backlight unit200 is divided into a plurality of blocks to be driven for each of thedivided blocks, and decreases the luminance of a black/dark part of animage and increases the luminance of a bright part of the image bylinking the luminance of each of the divided blocks with the luminanceof the video signals so as to improve a contrast ratio and sharpness ofthe image.

For example, when the backlight unit 200 is driven in a local dimmingscheme, the display panel 100 may have a plurality of division regionsto correspond to the blocks of the backlight unit, respectively. Thebrightness of the light emitted from each of the blocks of the backlightunit 200 may be adjusted depending on a luminance level of each of thedivision regions of the display panel 100, e.g., a peak value of a graylevel or a color coordinate signal.

That is, the plurality of light sources included in the backlight unit200 may be divided into the plurality of blocks and may be driven foreach of the divided blocks.

The block is a basic unit to which a specific driving power for drivingthe corresponding light sources in that block is applied. That is, thelight sources included in one block are turned on or turned off at thesame time and when the light sources in one block are turned on, theselight sources in one block may emit light having the same luminance.Further, the light sources included in different blocks in the backlightunit 200 may emit lights having different luminances by being suppliedwith different driving powers.

By configuring the backlight unit 200 by assembling the plurality ofoptical assemblies 10 according to the invention, it is possible tosimplify a manufacturing process of the backlight unit 200 and improveproductivity by minimizing a loss which can be generated in themanufacturing process. Further, the backlight unit 200 has an advantageapplicable to backlight units having various sizes through massproduction by standardizing the optical assembly 10.

Meanwhile, when any one of the plurality of optical assemblies 10provided in the backlight unit 200 has a failure, only the opticalassembly having the failure has to be replaced without replacing theentire backlight unit 200. Therefore, a replacing work is easy and apart replacement cost is saved.

FIG. 44 is a cross-sectional view illustrating a configuration of adisplay apparatus according to an embodiment of the present invention.Description of the same components of the illustrated display apparatusas those explained by referring to FIGS. 1 to 43 will now be omitted.The display apparatus of FIG. 44 can be the display apparatus having thebacklight unit(s) and other features discussed in connection with FIGS.1 to 43.

Referring to FIG. 44, the display panel 100 including the color filtersubstrate 110, the TFT substrate 120, the upper polarizer 130, and thelower polarizer 140, and the backlight unit 200 including the substrate210, the plurality of light sources 220, and the resin layer 230 canclosely adhere to each other.

For example, an adhesive layer 150 is formed between the backlight unit200 and the display panel 100, such that the backlight unit 200 can beadhesively fixed to the bottom of the display panel 100. Morespecifically, the top of the backlight unit 200 can adhere to the bottomof the lower polarizer 140 by using the adhesive layer 150.

The backlight unit 200 can further include a diffuse sheet (not shown)and the diffuse sheet (not shown) can closely adhere to the top of theresin layer 230. In this case, the adhesive layer 150 can be formedbetween the diffuse sheet (not shown) of the backlight unit 200 and thelower polarizer 140 of the display panel 100.

Further, a bottom cover 270 can be disposed in a lower part of thebacklight unit 200 and for example, as shown in FIG. 44, the bottomcover 270 can closely adhere to the bottom of the substrate 210. Thebottom cover 270 may be configured by a protection film for protectingthe backlight unit 200.

Meanwhile, the display apparatus can include a power supply unit 400 forsupplying driving voltages to the display module 20, e.g., the displaypanel 100 and the backlight unit 200. For example, the plurality oflight sources 220 provided in the backlight unit 200 are driven by usingthe voltages supplied from the power supply unit 400 to emit the light.

As shown in FIG. 44, the power supply unit 400 can be disposed and fixedonto the back cover 40 covering a back surface of the display module 20,such that the power supply unit 400 can be stably supported and fixed.

According to the embodiment of the present invention, a first connector410 can be formed on the substrate 210. For this, a hole or indentationfor inserting the first connector 410 therein can be formed in thebottom cover 270.

The first connector 410 electrically connects the power supply unit 400with the light source 220 to allow the driving voltage to be suppliedfrom the power supply unit 400 to the light source 220. For example, thefirst connector 410 is formed on the bottom of the substrate 210 and isconnected to the power supply unit 400 through a first cable 420 toallow the driving voltage supplied from the power supply unit 400 to betransmitted to the light source 220 through the first cable 420.

An electrode pattern (not shown), e.g., a carbon nanotube electrodepattern can be formed on the top of the substrate 210. The electrodeformed on the top of the substrate 210 is in contact with the electrodeformed in the light source 212 to electrically connect the light source220 with the first connector 410.

Further, the display apparatus can include a control unit 500 forcontrolling the driving of the display panel 100 and the backlight unit200. For example, the control unit 500 can be a timing controller. Thetiming controller controls a driving timing of the display panel 100.More specifically, the timing controller generates a signal forcontrolling the driving timings of a data driver unit, a gamma voltagegenerator, and a gate driver that are provided in the display panel 100to supply the generated signal to the display panel 100.

Meanwhile, the timing controller synchronizes with the driving of thedisplay panel 100 and can supply a signal for controlling the drivingtiming of the light sources 220 to the backlight unit 200, such that thebacklight unit 200, more specifically, the light sources 220 operate.

As shown in FIG. 44, the control unit 500 can be disposed and fixed ontothe back cover 40 covering a back surface of the display module 20, suchthat the control unit 500 can be stably supported and fixed.

According to the embodiment of the present invention, a second connector510 can be formed on the substrate 210. For this, a hole or indentationfor inserting the second connector therein 510 can be formed in thebottom cover 270. The second connector 510 electrically connects thecontrol unit 500 with the substrate 210 to allow a control signaloutputted from the control unit 500 to be supplied to the substrate 210.For example, the second connector 510 is formed on the bottom of thesubstrate 210 and is connected to the control unit 500 through a secondcable 520 to allow the control signal supplied from the control unit 500through the second cable 520 to be transmitted to the substrate 210.

Meanwhile, a light source driving unit can be formed in the substrate210. The light source driving unit can drive the light sources 220 byusing the control signals supplied from the control unit 200 through thesecond connector 510.

The configuration of the display apparatus shown in FIG. 44 is just oneexample of the present invention. Therefore, the positions or numbers ofthe power supply unit 400, the control unit 500, the first and secondconnector 410 and 420, and the first and second cables 420 and 520 canbe changed as necessary. For example, the first and second connector 410and 420 can be provided in each of the plurality of optical assemblies10 configuring the backlight unit 200 as shown in FIG. 43. The powersupply unit 400 or the control unit 500 can be disposed on the bottom ofthe bottom cover 270.

The present invention encompasses various modifications to each of theexamples and embodiments discussed herein. According to the invention,one or more features described above in one embodiment or example can beequally applied to another embodiment or example described above. Thefeatures of one or more embodiments or examples described above can becombined into each of the embodiments or examples described above. Anyfull or partial combination of one or more embodiments or examples ofthe invention is also part of the invention.

While the present invention has been described in connection withcertain exemplary embodiments, it is to be understood that the inventionis not limited to the disclosed embodiments, but, on the contrary, isintended to cover various modifications and equivalent arrangementsincluded within the spirit and scope of the appended claims, andequivalents thereof. For example, components specifically described ineach of the embodiments and examples of the present invention can bemodified. In addition, it should be appreciated that differences relatedto the modification and application fall within the scope of the presentinvention, which is prescribed in the appended claims.

What is claimed is:
 1. An optical assembly, comprising: a first layer; aplurality of light sources disposed over the first layer; a second layerthat is disposed above the first layer and covering the plurality oflight sources; and a pattern layer disposed above or in the secondlayer, wherein the pattern layer includes a plurality of patterns, whichare respectively corresponding to the plurality of light sources and areformed with a different material from the second layer by depositing,printing, or coating, each of the plurality of patterns corresponds toone of the plurality of light sources that is located closest to saideach of the plurality of patterns, at least one of the light sources hasa light emitting surface that faces a lateral direction and emits lightto the side, a center of at least one of the patterns is disposed apredetermined distance from a center of the corresponding closest lightsource in the lateral direction, and a width of each of the plurality ofpatterns in the lateral direction is greater than a width of thecorresponding closest light source in the lateral direction.
 2. Theoptical assembly according to claim 1, wherein at least one of the lightsources emits the light to the side at a predetermined orientationangle.
 3. The optical assembly according to claim 1, wherein at leastone of the patterns included in the pattern layer reflects at least partof light emitted from the plurality of light sources.
 4. The opticalassembly according to claim 1, wherein at least one of the patterns isformed on a transparent film and includes a plurality of dots.
 5. Theoptical assembly according to claim 4, wherein a density of theplurality of dots for the at least one of the patterns decreasesoutwardly from a portion of the at least one of the patterns.
 6. Theoptical assembly according to claim 5, wherein the portion of the atleast one of the patterns corresponds to a center portion of thecorresponding light source.
 7. The optical assembly according to claim1, wherein at least one of the patterns has a reflectance that decreasesoutwardly from a portion of the at least one of the patternscorresponding to a center portion of the corresponding light source. 8.The optical assembly according to claim 1, wherein at least one of thepatterns has a portion that transmits at least part of a light emittedfrom the corresponding light source.
 9. The optical assembly accordingto claim 1, wherein an outer edge portion of the at least one of thepatterns is aligned with a light emitting surface of said correspondinglight source.
 10. The optical assembly according to claim 1, wherein theat least one of the patterns in its entirety is disposed a predetermineddistance from a light emitting surface of said corresponding lightsource in the first direction.
 11. The optical assembly according toclaim 1, wherein an opening ratio of the pattern layer is at least 70%.12. The optical assembly according to claim 1, wherein at least one ofthe patterns has one of a circle shape, a cylinder shape, an oval shapeand a rectangle shape.
 13. The optical assembly according to claim 1,wherein at least one of the patterns includes at least one of metal andmetal oxide.
 14. The optical assembly according to claim 1, wherein atleast one of the patterns includes titanium dioxide (TiO₂).
 15. Theoptical assembly according to claim 1, wherein at least one of thepatterns is formed with pattern portions disposed above thecorresponding light source, the pattern portions having a convex shape,a concave shape, a semicircle shape, or a triangle shape.
 16. Theoptical assembly according to claim 1, wherein the second layer includesa plurality of particles.
 17. The optical assembly according to claim 1,further comprising: a third layer disposed above the second layer andthe pattern layer, wherein the third layer includes a plurality ofparticles.
 18. The optical assembly according to claim 1, wherein athickness of the second layer is approximately 0.1 to 4.5 mm.
 19. Theoptical assembly according to claim 1, wherein the second layerencapsulates the plurality of light sources on the first layer.
 20. Abacklight unit, comprising: at least one optical assembly of claim 1.21. A display apparatus, comprising: a backlight unit including at leastone optical assembly of claim 1; and a display panel positioned abovethe backlight unit, wherein the backlight unit is divided into aplurality of blocks and is selectively drivable for the divided blocks.22. The display apparatus according to claim 21, wherein the lightsources of the backlight unit are disposed to correspond to a displayregion of the display panel.
 23. The display apparatus according toclaim 21, wherein the display panel is divided into a plurality ofareas, and a luminance of light emitted from one of the blocks of thebacklight unit corresponding to one of the areas is adjusted dependingon a gray level peak value or a color coordinate signal of the areas.24. An optical assembly, comprising: a first layer; a plurality of lightsources disposed over the first layer; and a second layer disposed abovethe first layer and covering the plurality of light sources, the secondlayer including a plurality of patterns respectively corresponding tothe plurality of light sources for selectively reflecting light emittedfrom the plurality of light sources, wherein each of the plurality ofpatterns corresponds to one of the plurality of light sources that islocated closest to said each of the plurality of patterns, the pluralityof patterns are formed by depositing, printing, or coating, at least oneof the light sources has a light emitting surface that faces a lateraldirection and emits light to the side, a center of at least one of thepatterns is disposed a predetermined distance from a center of thecorresponding closest light source in the lateral direction, and a widthof each of the plurality of patterns in the lateral direction is greaterthan a width of the corresponding closest light source in the lateraldirection.
 25. The optical assembly according to claim 24, wherein theplurality of patterns are formed on the second layer or in the secondlayer.
 26. The optical assembly according to claim 24, wherein athickness of the second layer is approximately 0.1 to 4.5 mm.